procedure TForm1.Button1Click(Sender: TObject);
type
  cp_string = type AnsiString(65001);
var
  s_ansi: AnsiString;
  s_utf8: utf8string;
  s_unicode: string;
  s_cp: cp_string;
  s_raw: RawByteString;
  ts: TStringList;
  bb: TBytes;
begin
  s_ansi := 'Contacts - Контакты - 世界您好';
  s_utf8 := 'Contacts - Контакты - 世界您好';
  s_unicode := 'Contacts - Контакты - 世界您好';
  s_cp := 'Contacts - Контакты - 世界您好';
  //
  Label1.Caption := s_ansi + ' > ' + IntToStr(StringCodePage(s_ansi));
  Label2.Caption := s_utf8 + ' > ' + IntToStr(StringCodePage(s_utf8));
  Label3.Caption := s_unicode + ' > ' + IntToStr(StringCodePage(s_unicode));
  //
  ts := TStringList.Create;
  try
    Label4.Caption := s_cp + ' > ' + IntToStr(StringCodePage(s_cp));
    ts.Append(s_cp);
    Label5.Caption := ts.Text;
    s_raw := s_ansi;
    SetCodePage(s_raw, 65001, true);
    Label6.Caption := s_raw + ' > ' + IntToStr(StringCodePage(s_raw));
  finally
    ts.Free;
  end;
  //
  bb := TEncoding.Convert(TEncoding.Unicode, TEncoding.UTF8, TEncoding.Unicode.GetBytes(s_unicode));
  Label7.Caption := TEncoding.UTF8.GetString(bb);
end;

function Text2Hex(Msg: RawByteString): string;
var
  I: Integer;
begin
  Result := EmptyStr;
  for I := 1 to Length(Msg) do
  begin
    Result := Result + Inttohex(Ord(Msg[i]), 2);
  end;
end;

function Hex2Text(HexText: string): string;
var
  I: Integer;
begin
  Result := EmptyStr;
  for I := 1 to Length(HexText) div 2 do
    Result := Result + AnsiChar(StrToInt('$' + Copy(HexText, (I - 1) * 2 + 1, 2)));
end;

procedure TForm1.Button2Click(Sender: TObject);
var
  s: string;
  r: RawByteString;
begin
  s := Text2Hex(#$4C#$A1);
  s := Hex2Text(s);
  r := s;
  //
  Label8.Caption := r;
  Label9.Caption := IntToStr(Ord(r[2]));
end;